You have to know that Apple company knows where you are every time you connect your iPhone to iTunes. When you connect your gadget to iTunes it sends diagnostic logs to Apple. You can look at these logs if you want. I can show you how to do that on Windows, just go to: C:\Documents and Settings\\Application Data\Apple Computer\Logs\CrashReporter\MobileDevice\\Baseband and you will see a lot of these logs. Every log file points how many times your iPhone disconnected from network, dropped a call. For example: 18:13:43 -0400 DST clm disconnect: duration=57;cause=kNoError;ceer=0;txPower=-39;maxTxPower=0;rat=0;cgi=310:410:57226:29326 If you look at last numbers you can see that it is your IMSI number: 310 = Country Code for USA 410 = Operator code for AT&T 57226:29326 = numbers of your SIM where Apple see your Area and Cellsite. For more infor about IMSI number you can find here. But today I want show you how to log your iPhone baseband in real-time. Baseband logging creates baseband state dumps which are stored in binary format if you synchronize your iPhone with iTunes. These are generally series of files, quite big, and the two, will be sent manually back to Apple company.

How to log the iPhone Baseband in realtime.

All you need to do to log your iPhone baseband is to add these commands from SSH or Mobile terminal (install SSH you can here and Mobile Terminal here):
rm /dev/console
mknod /dev/console c 4 0
kill -USR1 `ps ax|grep omm|grep ys|xargs|cut -d ' ' -f 1`
kill -HUP `ps ax|grep omm|grep ys|xargs|cut -d ' ' -f 1`

How to stop the baseband log.

Also you can stop baseband log. To do that just add these commands:
rm /dev/console
mknod /dev/console c 1 0
kill -USR1 `ps ax|grep omm|grep ys|xargs|cut -d ' ' -f 1`

Quick Note about the nodes.

Warning: Don't use dev/tty.baseband for loging the baseband in real time. Use /dev/console as we are dumping the bb log on the console.

log iPhone baseband

There are some other ways to log the baseband.

Another way to log your iPhone baseband in real time is using the iPhone Configuration Utility. This utility enables you to see the syslog on your iPhone in real time. iPhone Configuration Utility allows you to easily generate, manage, encrypt, and push settings profiles, track and install provisioning profiles and approved apps, and capture gadget info together with console logs. So you can use links below to download iPhone configuration utility for Mac and Windows.

Download iPhone Configuration Utility 3.5:

Download for  Windows. Download for Mac OS. As well as the developer tools supplied by Apple, however the Console app will log failures for the mobile gadgets too if you're on a Mac. Moreover, each failure log item is saved on your desktop in:
~/*your_user*/Library/Logs/CrashReporter/MobileDevice/*your_phone*/
It's likely more of a technical report than something of value, but if you are finding a consistent issue with your app, it's certainly something that the developer would want to see. Now you know how to generate baseband state dumps using baseband logging in two different ways. Leave your questions and suggestions in the comment section below and I will consider them.